Epigenetic regulation constitutes a fundamentally important set of gene control mechanisms that profoundly influence chromatin function, with direct relevance to a large number of human diseases. Histone lysine methylation and demethylation are components of a histone code, and the recognition of these methyl marks underlies epigenetic regulation. For example, overexpression of a histone lysine demethylase, PHF8, has been noted in primary prostate cancer samples, where it is associated with increased invasiveness and a poorer prognosis. The inherently reversible nature of epigenetic modifications makes enzymes that modify histones and DNA attractive candidates for therapeutic intervention. Thus far such epigenetic therapies have focused on the enzymes that regulate histone acetylation and DNA methylation, with several HDAC and DNMT inhibitors now in clinical use and FDA approved for the treatment of leukemias and other cancers. The enzymes involved in regulating histone methylation patterns and levels have emerged as highly promising therapeutic targets, with newer histone methyltransferase inhibitors recently entering preclinical testing. Histone lysine demethylases (belong to a broad family of non-heme Fe(II)-dependent dioxygenases), on the other hand, remain a relatively untapped source of potential druggable targets. The central goal of this proposal is to validate, re-design, and synthesize small molecule inhibitors of histone lysine demethylases in vitro, and to investigate the mechanism(s) of inhibition by nature (iso)flavone derivatives.